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Re: [ATM] RC cass secondary and starlaps.

Interesting! So, this is the secondary? What tests are you using?

Dominic


On Wed, 28 Nov 2007, Jim Burrows wrote:

> I have finally, FINALLY, gotten the wavefront RMS down to 32.1 nm on
> my 10" RC cass (one test only, more to come, and if they agree, on to
> a star test).
>
> I've been using starlaps for figuring the secondary, many, many laps
> with 4 petals and only very small RMS improvements.  3 or 4 spells
> ago, I tried 3 petals - WOW, big difference!  The RMS went from 106
> down to the 32.  I'm guessing there might be a little physics going
> on here - if one petal of a 4-petal lap wears down, the mirror-lap
> contact may be determined by the other 3 petals, like a stable
> 3-legged stool, but then the overall shape of the lap would be incorrect.
>
>          -- Jim Burrows
>          -- http://home.earthlink.net/~burrjaw
>          -- mailto:burrjaw@earthlink.net
>          -- Seattle N47.4723 W122.3662 (WGS84)
>
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> ATM mailing list http://www.atmlist.net/
>

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